Is it possible to build an elevator for a treehouse using water and pulleys or gears?

Hello, I am attempting to build an ecolodge comprised of several treehouses and I would like it to be handicap accessible. I want to be as environmentally conscious as I can and I would like to know if anyone out there would have any ideas as to how an outside elevator could be constructed using water, pulleys, or gears that would also look as if it belonged next to the tree if you know what I mean.

One rope at each corner of the elevator, bring them straight up, pulleys that straighten out the rope and bring them to a crank wheel, which is then in turn, cranked to hoist the person up.

Another option, if you have a river or waterfall with a strong enough flow, is to use some alteration of a Ferris wheel or water bucket wheel(like in the Swiss Family Robinson treehouse). In addition to that design, if you don't have such a flow, you could always use water buckets or cauldrons as counterweights to the person, and just pour in as much water as is needed to lift them.

If there is a strong flow of water, you could also use some form of mill design, and make it so that a lever has to be pulled to put the gears together that would lift the elevator or lower it.

You could use a floating piston design. I have never actually seen one used so I may have just come up with off the top of my head. It's similar to single acting hydraulic cylinders that are used all the time for industrial elevators, except there is no seal between the piston and cylinder wall. You would need to dig a hole under the elevator car a bit deeper then the height you want to lift. Line the hole with a pipe (capped on the bottom) and drop a tree trunk in there. Filling the hole with water will cause the tree trunk to float up, taking with it what ever you put in the elevator car you built on top of the trunk. Pumping the water out would lower you to the ground.

Better than a tree trunk, you could use a sealed container at the bottom of a 4x4 post. This would mean less dead weight you have to displace, which just translates into a deeper hole you need to dig. This would also allow you to have an emergency release in the car that would lower the elevator. You would need a small opening in the bottom of container and a hose up to the cab with a valve. Opening it would allow water to flood the container and allow it to sink. Although, this would mean a still deeper hole because the air in the container is now compressible as the water level gets higher and would be less buoyant.

Another problem unique to this design is that the car will not stay put at the top station when you get on or off because of your weight. This can be fixed by adding cables that are attached to the car and the ground. Adjust the length so that the car can only ascend to exactly the correct position. You will need to remember to add a bit of extra water when raising the elevator up with no load in it so that it won't sink down when you step in.

Assuming a 200 lbs load + 100 lbs for the elevator car and an 8" pipe, you woud need to dig a hole your lift height + an extra 15' for the buoyancy container (assuming a 7 3/4" diameter container for clearance. Making a pipe from 55 gal drums (22.5" diameter) would mean a hole the lift height + only 1' 10" Adding the emergency release would increase these figures, but how much is a bit over my head at the moment.

I'm planning on using a guide pole that the elevator slides up. Should the cable break the weight on the platform will cause it to tilt and squeeze the guide pole. The resulting friction will stop the platform. Ever see pump jacks. They work in a similar manner, have been in use for years, and are OSHA rated. My elevator will be loaded and tested with dead weight, including the emergency braking system, before I will allow it to be used by my kids. The spirit of the America settlers lives on in my soul. Are we that dependent on government that we can not design and test our own solutions using simple principals of physics? I say no.

. Pump jacks are not designed for shock loads. They are designed for steady loads and can/will slip if you try to engage them when there is relative motion. . Being "OSHA rated" does not mean a piece of equipment is inherently safe. . You cannot legally install just anything to transport ppl. The things have to be built with very high safety factors, have to be inspected and licensed, &c. I strongly urge you to consult with an engineer before you need a lawyer.

Don't let anyone tell you an elevator can't be designed to be safe. I'm planning to build a tree house in a few weeks. I bought a used man-rated hand crank winch to raise and lower the elevator platform. These winches are used to lower workers into manholes or in rescue situations. They are OSHA rated, which means they have a 10-1 safety factor. The winch I have is rated for 350 lbs., but will actually lift 3,500 lbs due to the safety factor. I chose a hand crank winch so the older kids can get the younger kids and dog up to the treehouse using the elevator. The man rated winches have an automatic brake which stops the cable once the operator lets go of the crank. Regular boat trailer winches are not OSHA rated and do not have the automatic brake, so they would not be suitable to lift people. Man rated winches are expensive if purchased new $800 and up, however I bought a used one on Craigslist for $150. I'm planning on installing a square aluminum tube (won't rust like steel) from the ground up to the tree house to use as a guide rail for the elevator. Using a guide rail will prevent the elevator platform from swaying, tilting, or twisting while the platform is moving. Not sure how I'm going to construction the elevator platform yet. I'm thinking of making a cage out of square aluminum tubing. Aluminum is light weight, strong, and will not rust. If you want additional info on tree house elevator design email me: treehouse@kroppmail.com. No spam please.